Straight and tuning left is fine, no issues. As soon as you begin turning right, the RPM’s begin dropping. The sharper the right turn, the worse the power loss is. Straighten out and everything goes back to normal. Does this every time you turn right. It is not intermittent.
My 2012 Tahoe Q5i with a 2022 4.3 Mercruiser engine loses power when turning right. It drops rpms and gets worse the sharper the turn is. Took it to a boat mechanic who was unable to diagnose the problem.